Prior methods for fabricating an extended pinned layer are limited by an inadequate milling margin, possibly caused by the barrier layer thickness (approximately 10 angstroms), and the poor selectivity between the different materials in the TMR stack. In addition, use of a photoresist (PR) with ion beam milling may be responsible for producing free layer and bias residue on the back edge of the read head during definition of the sensor stripe. FIG. 1A illustrates a transmission electron microscope (TEM) image of a read sensor along an APEX direction. The TEM image of FIG. 1A shows a sensor stack that includes a barrier layer and a free layer (FL). In addition, a thick layer of FL residue is shown behind the sensor stripe. A different view of a read sensor along the ABS direction is illustrated in FIG. 1B. A TEM image of a different read sensor is shown in FIG. 1B along the ABS direction. A thick layer of bias residue is shown behind the sensor stripe of FIG. 1B produced using a prior process. The residue contamination shown in FIGS. 1A and 1B impairs the reliability and performance of conventionally-processed TMR heads. Therefore, a need exists for a process that overcomes the aforementioned limitations.